A variety of different shoe constructions are used by the footwear industry. For the most part, each shoe construction has characteristics that make it particularly well-suited for specific applications. For example, some shoe constructions are selected for their durability, others for their flexibility and comfort, while still others are selected for their aesthetic appeal.
In general, shoe construction typically involves a number of manufacturing operations or steps. Normally, a significant number of manufacturing operations generally results in a more expensive shoe. In a market where competitive price is often desired, there appears to be a need to make shoes in an efficient manner. Some shoe constructions may involve an upper being stitched to a forepart of an outsole by a hand stitch and the rearpart of the outsole may be attached to the upper by adhesive after a lasting operation. Lasting is typically where a last, an object which simulates a user's foot, is inserted into the upper and the upper is often then pulled taught around the last and secured to a tuck, which is removably attached to the bottom of the last. The tuck generally provides a structure that is adhered to the rearpart of the outsole, which in turn results in the upper being secured to the outsole in the rearpart of the shoe. Without a tuck, it may be difficult to secure the upper to the outsole.
A traditional insole is often wrapped with a wrapper around its peripheral edge to help prevent the edge of the insole from wear. The insole with the wrapper is then typically secured to the tuck or outsole. In a separate operation, a socklining may then be adhered directly to the top of the insole for providing a surface adapted to receive a user's foot because the insole's surface is often coarse.
In addition to or instead of the above mentioned construction, cementing components of a shoe, such as the upper to the outsole, often involves a number of manufacturing operations. Typically, there is a surface preparation step where the surfaces to be cemented, or glued, are clean of debris and readied, which may also include roughening. Further, there may be an application step where the cement is applied to the surfaces. This step may also involve measuring and evenly distributing the glue over the surface.
Further, there may be a pressing step where the surfaces are pressed together. Pressing is believed to reduce air that may be trapped between the surfaces and enhances adhesion. Pressing may also include aligning the surfaces so that the peripheries of the components are flush with one another.
Additionally, once the components are pressed together, cementing often requires a waiting period for the cement to cure, or dry. Generally, not only does cementing involve some or all of the above mentioned manufacturing operations, it also involves time, particularly the curing time.
It is believed that the number of steps and time involved, especially if user intervention is required, negatively affects cost and efficiency. The cementing process may be further complicated if the surfaces to be glued are uneven or difficult to reach.
U.S. Pat. No. 5,369,895 to Hammerschmidt and U.S. Pat. Nos. 4,476,600, 4,408,401 and 4,505,660 to Seidel appear to relate to a shoe having a one piece construction. The one piece construction may reduce manufacturing steps to secure the upper to the outsole.
U.S. Pat. No. 4,742,625 to Sydor appears to relate to a shoe having a one piece construction and channels in the sole for ventilating the shoe. Sydor also appears to include a removable insole without ventilation channels.
Moreover, ventilating a shoe may be preferred as historically constructed footwear often confine the foot and usually lacks sufficient breathability, which may cause the foot to perspire and may also promote the development of bacteria, fungi and the like as well as any accompanying unpleasant odors and skin problems.
Some later developed footwear may attempt to solve the lack of sufficient breathability by providing openings in the upper but such openings may also allow debris and water to enter the shoe. U.S. Pat. No. 6,564,475 to Collins, U.S. Pat. No. 5,086,576 to Lamson, U.S. Pat. No. 6,553,690 to Di Girolamo, and U.S. Pat. No. 5,992,052 to Morris appear to relate to footwear with vent holes in the upper, sole, or both. Although these references may have vent holes in either the upper or sole, breathability is possibly still inadequate since the shoe lacks a mechanism that causes atmospheric air to enter the shoe and hot air within the shoe to exit the shoe.
Complicated valve arrangements may have been provided by other constructions to open and close an opening to reduce the amount of debris or water entering the shoe. However, these types of footwear may generally be more expensive to purchase. U.S. Pat. No. 6,282,813 to Squadroni and U.S. Pat. No. 5,992,052 to Moretti appear to relate to footwear having valves for venting the shoe.
Other approaches may include a pump encased within the shoe, sometimes in communication with openings in the upper. Generally, the weight of the foot is used to compress the pump and force air out of apertures to ventilate the foot. However, problems may arise if the pump fails to reinflate, which often occurs because the foot is typically placed on top of the pump and prevents full inflation. Moreover, such mechanisms are typically prohibitively expensive to build into footwear and, given that most of these devices are built into the shoe, they are not easily repairable or replaceable. U.S. Pat. No. 4,835,883 to Tetrault and U.S. Pat. No. 4,776,110 to Shiang and U.S. Publication No. 2002/0011009 to Pan appear to relate to footwear having pumps.
What is desired, therefore, is a shoe constructed in a more efficient manner without sacrificing quality. What is also desired is a shoe having a reduced number of manufacturing steps. What is further desired is a shoe having improved ventilation. Yet another desire is a shoe that has a ventilation system that cools the user's foot and provides sufficient breathability. A still further desire is a shoe with a ventilation system that reduces the amount of debris or water that enters the shoe. Yet another desire is a shoe that has a ventilation system that is reliable and inexpensive.